This invention relates generally to forming of, and to formed, glass fiber composites, as are used in high-efficiency air filtration; and more particularly the invention concerns a glass fiber filter media composite wherein glass fibers have various diameters to produce distinct advantages.
There is need for longer-life filters capable of efficiently filtering particulate from gas streams, and there is need for efficient, effective methods of producing such filters. The disclosure of U.S. Pat. No. 3,690,852, incorporated herein by reference, concerns production of a filter comprising two layers of fibers of different sizes. The present invention improves upon the filter described in that patent, as will be seen.